NGS-based oncogenic mutations analysis in advanced colorectal cancer patients improves targeted therapy prediction

Immunolipid magnetic bead-based circulating tumor cell sorting: a novel approach for pathological staging of colorectal cancer

Objective

This study aimed to assess whether circulating tumor cells (CTCs) from colorectal cancer (CRC) could be used as an alternative to tissue samples for genetic mutation testing, overcoming the challenge of difficult tumor tissue acquisition.

Methods

We developed an immunolipid magnetic bead (IMB) system modified with antibodies against epithelial cell adhesion molecule (EpCAM) and vimentin to efficiently separate CTCs. We prepared EpCAM-modified IMBs (Ep-IMBs) and vimentin-modified IMBs (Vi-IMBs). The separation efficiency of the system was evaluated via in vitro experiments and by capturing and counting CTCs in blood samples from 23 CRC patients and 20 healthy controls. Hotspot mutations in patient tissue samples were identified via next-generation sequencing (NGS), whereas mutations in blood CTCs were detected via Sanger sequencing. The concordance between hotspot mutations in tumor tissue and blood CTCs was analyzed.

Results

The CTC sorting system exhibited good dispersion, stability, and low cytotoxicity, with a specificity of 90.54% and a sensitivity of 89.07%. CRC patients had an average of 8.39 CTCs per 7.5 mL of blood, whereas healthy controls had 0.09 per 7.5 mL of blood. The consistency of gene mutations was as follows: TP53 (91.31%), PIK3CA (76.00%), KRAS (85.36%), BRAF (51.00%), APC (65.67%), and EGFR (74.00%), with an overall gene mutation consistency of 85.06%.

Conclusion

Our CTC sorting system, which is based on Ep-IMBs and Vi-IMBs, effectively captures CTCs in the peripheral blood of CRC patients and enables clinical hotspot gene mutation testing via these enriched CTCs. This system partially solves the problem of difficult tumor tissue sample collection and provides a reference for gene mutation testing in early diagnosis, therapeutic efficacy evaluation, prognosis assessment, and minimal metastasis detection in CRC patients, showing significant potential for clinical application, especially in targeted therapy gene testing for CRC.

Targeted variant prevalence of FBXW7 gene mutation in colorectal carcinoma propagation. The first systematic review and meta-analysis

FBXW7 is a tumour suppressor gene that functions as E3-ubiquitin-ligase, targeting numerous oncoproteins for degradation, i.e., Cyclin-E, c-Myc, and Notch. FBXW7 performs a pivotal role in regulating cell cycle progression. FBXW7 mutation is frequently implicated in various cancers.

Methodology

A systematic review and meta-analysis done on several studies using "Preferred Reporting Items for Systemmatic Reviews and Meta-Analysis (PRISMA)" criteria and registered with PROSPERO (registration-number-CRD42023388845). The preliminary search comprises 1182 articles; however, 58 studies were subsequently chosen after eliminating non-eligible studies. To explore the prevalence of FBXW7 mutation among colorectal cancer patients, data were analysed using "OpenMeta Analyst and comprehensive meta-analysis-3.0 (CMA-3.0)" software.

Results

This meta-analysis involves 13,974 respondents; most were males 7825/13,974, (56.0 %). Overall prevalence of FBXW7 mutations was 10.3 %, (95%CI: 8.6-12.4), I2 = 90.5 %, (P < 0.001). The occurrence of FBXW7 mutations was highest in Russia [19.0 %, (95%CI: 9.8-33.7)] and Taiwan [18.8 %, (95%CI: 8.7-35.9)], P-values< 0.05 while the least prevalence was reported in Netherland (4 %) and Italy (5 %), both P-values< 0.001. Overall prevalence of FBXW7 abberation was greatest amongst male gender: "53.9 %, (95%CI: 8.3-62.0 %)", Tumour location (colon): 59.8 %, (95%CI: 53.9-65), tumour site (left): 61.6 %, (95%CI: 53.8-68.9), Tumour-grade (Moderate): 65.9 %, (95%CI: 54.9-75.4 %), and Tumour late-stage: 67.9 %, (95%CI: 49.7-84.3 %), all P-values< 0.001. When stratified according to study-period, an increasing trend was noted from 2018 till present with the highest mutation rate recorded in 2022 (15.3 %).

Conclusion

Overall prevalence of FBXW7 mutations was 10.3 % with male gender, left side, and late-stage being most mutated, and these outcomes conform with severally published articles on FBXW7 mutation.

Prevalence of KRAS G12C Mutation and Co-mutations and Associated Clinical Outcomes in Patients With Colorectal Cancer: A Systematic Literature Review

PURPOSE

A systematic literature review was conducted to estimate the global prevalence of Kirsten rat sarcoma virus gene (KRAS) mutations, with an emphasis on the clinically significant KRAS G12C mutation, and to estimate the prognostic significance of these mutations in patients with colorectal cancer (CRC).

DESIGN

Relevant English-language publications in the Embase, MEDLINE, and the Cochrane Library databases (from 2009 to 2021) and congress presentations (from 2016 to 2021) were reviewed. Eligible studies were those that reported the prevalence and clinical outcomes of the KRAS G12C mutation in patients with CRC.

RESULTS

A total of 137 studies (interventional [n = 8], post hoc analyses of randomized clinical trials [n = 6], observational [n = 122], and longitudinal [n =1]) were reviewed. Sixty-eight studies reported the prevalence of KRAS mutations (KRASm) in 42 810 patients with CRC. The median global prevalence of KRASm was 38% (range, 13.3%-58.9%) and that of the KRAS G12C mutation (KRAS G12C) 3.1% (range, 0.7%-14%). Available evidence suggests that KRASm are possibly more common in tumors that develop on the right side of the colon. Limited evidence suggests a lower objective response rate and inferior disease-free/relapse-free survival in patients with KRAS G12C compared with patients with KRASwt or other KRASm.

CONCLUSION

Our analysis reveals that KRAS G12C is prevalent in 3% of patients with CRC. Available evidence suggests a poor prognosis for patients with KRAS G12C. Right-sided tumors were more likely to harbor KRASm; however, their role in determining clinical outcomes needs to be investigated further.

Fecal gene detection based on next generation sequencing for colorectal cancer diagnosis

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Given its insidious onset, the condition often already progresses to advanced stage when symptoms occur. Thus, early diagnosis is of great significance for timely clinical intervention, efficacy enhancement, and prognostic improvement. Featuring high throughput, fastness, and rich information, next generation sequencing (NGS) can greatly shorten the detection time, which is a widely used detection technique at present.

AIM

To screen specific genes or gene combinations in fecal DNA that are suitable for diagnosis and prognostic prediction of CRC, and to establish a technological platform for CRC screening, diagnosis, and efficacy monitoring through fecal DNA detection.

METHODS

NGS was used to sequence the stool DNA of patients with CRC, which were then compared with the genetic testing results of the stool samples of normal controls and patients with benign intestinal disease, as well as the tumor tissues of CRC patients. Specific genes or gene combinations in fecal DNA suitable for diagnosis and prognostic prediction of CRC were screened, and their significances in diagnosing CRC and predicting patients' prognosis were comprehensively evaluated.

RESULTS

High mutation frequencies of TP53, APC, and KRAS were detected in the stools and tumor tissues of CRC patients prior to surgery. Contrastively, no pathogenic mutations of the above three genes were noted in the postoperative stools, the normal controls, or the benign intestinal disease group. This indicates that tumor-specific DNA was detectable in the preoperative stools of CRC patients. The preoperative fecal expression of tumor-associated genes can reflect the gene mutations in tumor tissues to some extent. Compared to the postoperative stools and the stools in the two control groups, the pathogenic mutation frequencies of TP53 and KRAS were significantly higher for the preoperative stools (χ 2 = 7.328, P < 0.05; χ 2 = 4.219, P < 0.05), suggesting that fecal TP53 and KRAS genes can be used for CRC screening, diagnosis, and prognostic prediction. No significant difference in the pathogenic mutation frequency of the APC gene was found from the postoperative stools or the two control groups (χ 2 = 0.878, P > 0.05), so further analysis with larger sample size is required. Among CRC patients, the pathogenic mutation sites of TP53 occurred in 16 of 27 preoperative stools, with a true positive rate of 59.26%, while the pathogenic mutation sites of KRAS occurred in 10 stools, with a true positive rate of 37.04%. The sensitivity and negative predictive values of the combined genetic testing of TP53 and KRAS were 66.67% (18/27) and 68.97%, respectively, both of which were higher than those of TP53 or KRAS mutation detection alone, suggesting that the combined genetic testing can improve the CRC detection rate. The mutation sites TP53 exon 4 A84G and EGFR exon 20 I821T (mutation start and stop positions were both 7579436 for the former, while 55249164 for the latter) were found in the preoperative stools and tumor tissues. These "undetected" mutation sites may be new types of mutations occurring during the CRC carcinogenesis and progression, which needs to be confirmed through further research. Some mutations of "unknown clinical significance" were found in such genes as TP53, PTEN, KRAS, BRAF, AKT1, and PIK3CA, whose clinical values is worthy of further exploration.

CONCLUSION

NGS-based fecal genetic testing can be used as a complementary technique for the CRC diagnosis. Fecal TP53 and KRAS can be used as specific genes for the screening, diagnosis, prognostic prediction, and recurrence monitoring of CRC. Moreover, the combined testing of TP53 and KRAS genes can improve the CRC detection rate.

The Potential Role of Genomic Signature in Stage II Relapsed Colorectal Cancer (CRC) Patients: A Mono-Institutional Study

Purpose

The absolute benefit of adjuvant chemotherapy in stage II CRC is only 3–4%. The identification of biomarkers through molecular profiling could identify patients who will more benefit from adjuvant chemotherapy.

Patients and Methods

This retrospective analysis examined tissue blocks from 17 patients affected by relapsed stage II CRC, whose comprehensive genomic profiling of tumors was conducted through next-generation sequencing (NGS) via Roche-FoundationOne^®.

Results

Mutations were found in APC (76.5%), TP53 (58.8%) and KRAS (52.9%). Only KRAS wild-type samples showed FBXW7. APC frameshift mutations and MLH1 splice variant were conversely significant correlated (7% v 93%, P = 0.014). The median number of gene mutations reported was 6 (range 2–14). The TP53 mutation was associated most frequently with lung metastasis (P = 0.07) and high tumor budding (P = 0.03). Despite no statistical significance, lung recurrence, LVI/Pni, MSI and more than 6 genetic mutations were correlated to worse DFS and OS. Patients carried co-mutations of TP53-FBXW7 reported the worse DFS (4 v 14 months) and OS (4 v 65 months) compared to the other patients.

Conclusion

According to the present analysis, the setting of relapsed CRC emerges as one of the fields of greatest utility for NGS, looking at personalized cancer care.

The Clinical Versatility of Next-Generation Sequencing in Colorectal Cancer

Next-Generation Sequencing is an evolving technology employed in the field of cancer biology. This mini review is intended as a brief overview of NGS for the clinical utility in colorectal cancer. The pathogenesis and treatment of colorectal cancer will continue to evolve as NGS is applied to more patient samples, correlating tumor biology and outcomes.

Distinct clinical phenotype and genetic testing strategy for Lynch syndrome in China based on a large colorectal cancer cohort

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) predisposition syndrome. We performed a large-scale study to assess a screening strategy for identifying LS in Chinese CRC patients in routine clinical testing. A total of 4,195 eligible CRCs were universally screened. Then, 8.7% of CRCs were detected with dMMR. The incidence of LS was 2.7% (115 of 4,195) in this cohort; among patients over 70 years of age, only 0.3% (2 of 678) were diagnosed as LS. Then, 17.4% of LS cases showed large genomic deletions/duplications. LS probands developed CRCs predominantly at proximal colon location. The frequency of BRAF V600E mutation among Chinese CRCs was significantly lower than that among Western populations, and MLH1 promoter methylation significantly improved the efficiency of genetic screening for LS among MLH1-deficient patients. A comprehensive molecular testing strategy that includes detection of large genomic rearrangements is imperative for the diagnosis of LS. Among CRC patients aged 70 years or younger, a selective strategy for LS screening might be considered for routine clinical testing.

Positive Correlation Between Somatic Mutations in RAS Gene and Colorectal Cancer in Telangana Population: Hospital-Based Study in a Cosmopolitan City

Colorectal cancer (CRC) ranks among the most prevalent cancer types in both men and women. Screening of RAS (Kirsten rat sarcoma viral oncogene homolog (KRAS), neuro-blastoma RAS viral oncogene homolog (NRAS), and v-raf murine sarcoma viral oncogene homolog B1 (BRAF)) somatic mutations is necessary prior to considering anti-epidermal growth factor receptor (EGFR) therapies in CRC patients. Next-generation sequencing studies have confirmed that RAS gene panels could be used while developing treatment strategies for patients with CRC. The present study explored genetic mutations in KRAS, NRAS, and BRAF in CRC patients in the Telangana state of India. Patients with confirmed CRC (n = 100) who visited the Apollo hospitals were evaluated. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissues, and pyrosequencing analysis was performed. Patient DNA samples were screened for 54 different KRAS, NRAS, and BRAF mutations, which revealed 34 somatic mutations. Exon 11 of BRAF possessed 4 mutations with highest individuals documented with G469A mutation. Pyrosequencing, a reliable method for analyzing somatic mutations present in RAS, could aid in taking treatment decisions for patients with CRC.